From the introduction:
Acting upon information gained from hacker Bruce Wong during a previous operation (see the We’re Off To See The Wizard serial), the Agency now believes that a shadowy global organization is working toward a grander goal. As yet, the Agency knows very little about this organization — only that it hired Wong to design a computer virus targeting the New York Stock Exchange — and so the home office grants the hacker amnesty in exchange for details about the virus and his employers. During the ensuing debriefing, Wong reveals that he built a back door into his program that allows him to trace the user’s location. The Agency utilizes this back door to track operatives of the enemy organization to New York City, and sends a team of agents to investigate on the ground. The team is instructed to find the virus and prevent its activation. Their secondary mission objective is to ascertain as much information as possible about the enemy.